NoScript is basically an anti-Java/anti-cookie/anti-any-fucking-thing-you-don't-want-displayed Firefox
addon that's easy to install and use. Hell, I'm using it right now; Only UrbanDictionary is displayed, not those fucktarded ads on the side bar over yonder to this description's right.
If you don't want anything you don't know being displayed, like maybe a porn site when you stray off (since....y'know...parents...), download this.
Firefox in itself cuts down your virus intake by 70% (and I say THAT because people often Google incredibly fucking stupid torrent
sites with infested files. If you're me, it can pretty much mean internet surfing while turning off whatever system-pig scanner's running).
The only downside is you gotta remember to tell the fucker to allow sites you wanna see stuff from.